The present invention relates to an orientation mechanism for orienting objects whose surface comprises at least a bigger convex portion and at least a smaller projecting or bulging portion, such as mushrooms, pears, onions, flower bulbs and the like, provided with an endless conveyer member, comprising a number of conveying elements formed by drivable hourglass-shaped rollers, which are located adjacent each other and arranged transversely to the conveying direction, the rollers being spaced apart a specific distance one behind the other, such that the convex portion of objects to be oriented will be prevented from coming between the rollers.
Such mechanisme is known from EP-A-0518-209. In this document an apparatus is described for conveying and orienting fruits and for removing oriented fruits by means of a rotating pneumatic fruit engaging device. Particularly for mushrooms which must be subjected to further treatment, e.g. cutting the end part of the stipes of the mushrooms, such an apparatus is not appropriate.
A mechanisms for handling mushrooms is known from Dutch laid-open application 93.01363, relating to an apparatus for conveying harvested mushrooms to a cutting device. The endless conveying member known from this publication comprises a number of conveyor belts juxtaposed in the conveying direction and driven at different peripheral velocities, the arrangement being such that the mushrooms located thereon are oriented with either their caps, or their feet in leading position, so that they are presented to the cutting device in a predetermined position. This known apparatus has the drawback that the orientation of the mushrooms is not unequivocal, while, moreover, relatively heavy mushrooms standing with their caps on the conveying member are inclined to have their positions unchanged and, possibly, to rotate about their own longitudinal axes.
Such orientation problems do not merely occur in respect of mushrooms, but also in respect of all kinds of objects that are presented in a random position and which, for a further treatment or processing, should be oriented in a specific manner. In this connection, one should not only think of other natural products, such as onions, flower bulbs, pears and the like, but also of, for instance, wooden products or plastic products that can serve as decoration or toy, such as toadstools which, brought into a specific orientation, have to be automatically provided with various colors.
Hence, it is the object of the invention to avoid the above orientation problems entirely or at least to a considerable extent, and to provide an orientation mechanism by means of which all kinds of objects and in particular objects whose surface comprises at least a convex portion and at least a projecting or bulging portion, can be oriented unequivocally so that they can readily be further treated or processed.
To that end, in accordance with the invention, the orientation mechanism as described in the preamble is characterized in that the conveying elements are formed by rollers arranged transversely to the conveying direction and spaced apart a specific distance one behind the other, which rollers are movable in the conveying direction and are suitable for orienting objects, while further, separate carriers are present suitable for supporting oriented objects.
To provide a proper view of various preferred embodiments, it will, for the sake of simplicity, hereinafter be assumed that the objects are formed by mushrooms, of which the convex portion of the surface is formed by the caps and the projecting or bulging portion is formed by the stipes of the mushrooms. However, it is pointed out that all types of other objects are also suitable for being oriented by the mechanism in its various embodiments.
The rollers can be formed by rolls. Due to their rolling behavior, the mushrooms are rotated by the rolls until they end up with their stipes between the rolls, or come to lie on the rolls with their stipes directed forwards or rearwards; thus, the mushrooms have oriented themselves. However, if the stipe happens to be relatively long or curved at the end, a mushroom might not get across a roll and, consequently, does not orient itself. It also occurs that the mushrooms, rotating about their longitudinal axis, start moving along this axis; in that case, the position of the oriented mushrooms along the rolls is not completely defined. Hence, it is preferred that the rollers be of hourglass-shaped design. In particular, the hourglass-shaped rollers are manufactured from a synthetic material, such as rubber of PVC, and preferably, during their functioning, they are held in a dry or moist condition, depending on the surface of the objects to be oriented.
In contrast with the above-cited Dutch laid-open application, the carriers fitted in accordance with the invention, suitable for supporting the oriented mushrooms, are preferably of such design that the mushrooms are ultimately supported in vertical orientation; for this purpose, the carriers are in particular formed by ropes, belts or similar elements that are movable in the conveying direction. Hereinafter, for the sake of simplicity, reference will in each case be made to xe2x80x98ropesxe2x80x99, while it should be taken into account that whatever applies to ropes, also applies to xe2x80x98belts or similar elementsxe2x80x99. The ropes may be arranged within the range of the rollers for movement along with the rollers in the conveying direction. The effect thus achieved is that once the mushrooms are vertically oriented and, accordingly, further advanced while suspending between the ropes, they will remain in this position. In that case, it has in principle become impossible for them to roll any further. Preferably, downstream of the conveying member formed by the rollers, the ropes extend further over any desired distance. To ensure that during orienting, the mushrooms are not obstructed herein, the rollers are provided, at a particular distance from their two side faces, with circular slots or grooves through which the ropes run. This enables the ropes to be provided at a shorter distance from the horizontal plane through the center line of the rollers.
The ropes need not necessarily be provided for movement along with the rollers within the entire range of the rollers. A construction where the ropes connect to the rollers of the conveying member at the end face thereof could suffice. This means that the mushrooms on the conveying member can be oriented with their stipes in forward, rearward or vertical position, and are subsequently taken over in the vertical position by the ropes connecting to the conveying member. Instead of ropes connecting to the conveying member, for instance fork-shaped grippers accommodated in an endless chain track may also be employed. Such a solution, however, will be much more complex than the above-mentioned rope constructions.
Although a construction of the rollers in the form of hour-glasses is an improvement over a construction wherein the rollers are designed as rolls, the use of hourglass-shaped rollers may also involve non-orientation of the mushrooms. When the mushrooms come to rest with their caps in the deepest portion of the hourglass-shaped rollers and have their stipes pointing towards the lateral side, the stipes will laterally project from the conveying member if these stipes are longer than approximately half the length of the hourglass-shaped rollers. To enable orienting the mushrooms as yet in the desired manner in such a situation, in accordance with the invention, tilting members are provided on either side of the rollers in the conveying direction, which tilting members are suitable for orienting as yet objects not oriented by the rollers. In particular, these tilting members are formed by tilting belts having upright elements attached thereto. Although it is possible that the relative velocity of the tilting belts with respect to the forward velocity of the rollers is chosen to be less than or equal to the forward velocity of the rollers, it has proved to be favorable when the velocity of the tilting belts is greater than the forward velocity of the rollers. The effect thus achieved is that due to the upright elements, the stipes of the mushrooms that laterally project from the rollers are given a forwardly directed impulse in the rotational direction of the rollers and in the conveying direction, as a result of which the mushrooms can be moved into a position in which they ultimately adopt a vertical orientation.
To enable speeding up the treatment or processing of the objects, the velocity of the conveying member could be increased. However, this entails the drawback that the orientation of the objects may become rather restless. Hence, it is better to design the conveying member with several juxtaposed rows of conveying elements having carriers and rollers. Accordingly, in practice, instead of such so-called one-track machines, multi-track machines will be used.
Further, it is observed that in a favorable embodiment, the conveying member is of endless design, while the rollers that are movable in the conveying direction on the upper side have their lower side contacting a flat surface and are rotated through friction with said surface.
The invention does not only relate to an orientation mechanism, but also to an apparatus for processing objects, in particular objects whose surface comprises at least a convex portion and at least a projecting or bulging portion, such as mushrooms, pears, onions, flower bulbs and the like, provided with a supply member for these objects, a sorting member for selecting the objects according to size, and a processing member for the further processing of the objects. The invention is characterized in that between the sorting member and the processing member, an orientation mechanism of the above-indicated type is provided. A sorting member for selecting objects according to size is necessary when objects of varying sizes are treated or processed; after all, as far as its construction is concerned, the orientation mechanism according to the invention is entirely adapted to orienting objects of equal or approximately equal size, as is particularly the case in the processing of mushrooms.
Because a given percentage of the mushrooms cultured in the usual manner on beds and harvested mechanically or manually exhibits a so-called sandy base, while, further, customers increasingly impose requirements with regard to the length of the stipes in relation to the volume of the cap, it is desired that the stipes that are too long and/or have a sandy base can be cut off. For this, many cutting devices have been developed. For a number thereof, it is important that the mushrooms be oriented.
Hence, the invention further relates to an automatic mushroom processing apparatus characterized in that the mushrooms, selected according to size and oriented with their stipes downwards by means of an orientation mechanism of the above-indicated type, are supplied to an inspection and cutting member for signaling mushrooms with sandy bases or mushrooms whose stipes are too long, and for cutting off a part of the stipe.